International Journal of Structural Integrity最新文献

{"title":"Modification and application of notch equivalent stress method for fatigue assessment on welded structures","authors":"Bo Liu, Yue Wang, Zhe Zhang, Qi Dong","doi":"10.1108/ijsi-04-2023-0035","DOIUrl":"https://doi.org/10.1108/ijsi-04-2023-0035","url":null,"abstract":"PurposeThis paper aims to study and modify the notch equivalent stress method, as well as to establish the notch equivalent stress range S–N curve and apply it to the fatigue assessment of engineering examples.Design/methodology/approachThis paper studies the notch equivalent stress method and puts forward the concept of “singular equivalent crack”. Combined with the fatigue test results, by proposing to consider the singular coefficient of the transition angle of the welded structure and the introduction of material correction factors, this paper derives the notch equivalent stress equation for commonly used welded joints applicable to steel, and finally establishes the notch equivalent stress range of the S–N curve.FindingsThe obtained results show that the dispersion of fatigue data is 65.6 and 75.4% for T-joints and transverse cross-joints, respectively, under S–N curves using notched equivalent stress compared to the nominal stress range. The fatigue evaluation error of the modified notch equivalent stress equation for transverse cross welded joints improved by 50.65%, 53.1 and 39.6% on average, respectively, compared to the original other methods. The fatigue evaluation error for T-joints improved by 13.4 and 13.9%, respectively, compared to the original other methods.Originality/valueThere are relatively few studies on the fatigue assessment of notch equivalent stress method. In this paper, the notch equivalent stress method is studied and modified to improve the accuracy of fatigue assessment of welded structures with singular stresses.","PeriodicalId":45359,"journal":{"name":"International Journal of Structural Integrity","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2023-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45746351","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A multi-parameter method for static behaviour of headed stud with ductile fracture in push-off tests","authors":"Yixing Ding, Yanmin Jia, Jiangyue Li, Huiming Li, X. Zhang","doi":"10.1108/ijsi-03-2023-0017","DOIUrl":"https://doi.org/10.1108/ijsi-03-2023-0017","url":null,"abstract":"PurposeThe purpose of this study is to investigate the effects of stud height, stud diameter, ultimate stress of stud and concrete strength on the static behaviour of studs in push-off tests based on the ductile fracture theory.Design/methodology/approachPush-off tests of headed stud shear connectors with different heights and diameters used in concrete of various strengths were designed and implemented. A finite element model was established based on a ductile fracture criterion of ML15 cold-heading steel with stress triaxiality and Lode angle parameter. Based on the results of the parametric study of the numerical model, equations were proposed to evaluate the effect of stud height hs, stud area As, concrete strength fc and stud ultimate strength fsu used in concrete of various strengths on the static behaviour of studs.FindingsThe typical failure phenomenon observed among the test specimens was the fracture of the shank of studs. The microscopic images of the stud fracture surfaces and the verified finite element model indicate that the studs were fractured as a result of the combined action of tension and shear.Originality/valueA new method for calculating ultimate load Pu and ultimate slip Su is proposed in this paper. In the method, Pu is linearly related to fsu0.2143, As0.7790, hs0.0974, fc0.2065. Su is linearly related to fsu1.078, As0.4681, hs(−0.3135), fc(−0.3480).","PeriodicalId":45359,"journal":{"name":"International Journal of Structural Integrity","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2023-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48342268","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bandgap mechanisms and wave characteristics analysis of a three-dimensional elastic metastructure","authors":"Ying-Lin Li, Chenwei Wu, Yong-mei Peng, Xudong Jiang","doi":"10.1108/ijsi-09-2022-0118","DOIUrl":"https://doi.org/10.1108/ijsi-09-2022-0118","url":null,"abstract":"PurposeIn order to investigate the vibration reduction properties of a three-dimensional elastic metastructure with spherical cavities at low frequencies.Design/methodology/approachThe bandgap characteristics of a three-dimensional elastic metastructure with spherical cavities are studied based on analytical and numerical approaches.FindingsThe results of both method revealed that the vibration of the vertexes masses is important for opening bandgaps. The fact that the big sphere cavity radius or short side length of the cube unit leads to a wider bandgap, is noteworthy.Originality/valueThis research provides theoretical guidance for realizing the vibration attenuation application of EMs in practical engineering.","PeriodicalId":45359,"journal":{"name":"International Journal of Structural Integrity","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2023-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46655233","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Time-varying seismic resilience analysis of coastal bridges by considering multiple durability damage factors","authors":"Yan Liang, Yingying Wei, Panjie Li, Liangliang Li, Z. Zhao","doi":"10.1108/ijsi-12-2022-0147","DOIUrl":"https://doi.org/10.1108/ijsi-12-2022-0147","url":null,"abstract":"PurposeFor coastal bridges, the ability to recover traffic functions after the earthquake has crucial implications for post-disaster reconstruction, which makes resilience become a significant index to evaluate the seismic behavior. However, the deterioration of the material is particularly prominent in coastal bridge, which causes the degradation of the seismic behavior. As far, the research studies on resilience of coastal bridges considering multiple degradation factors and different disaster prevention capability are scarce. For further evaluating the seismic behavior of coastal bridge in the long-term context, the seismic resilience is conducted in this paper with considering multiple durability damage.Design/methodology/approachThe fuzzy theory and time-varying fragility analysis are combined in this paper to obtain the life-cycle resilience of coastal bridges.FindingsThe results show that durability damage has a remarkable impact on the resilience. After 100 years of service, the seismic resilience of bridge with poor disaster-prevention capability has greatest reduction, about 18%. In addition, the improvement of the disaster prevention capability can stabilize the resilience of the bridge at a higher level.Originality/valueIn this paper, the time-varying fragility analysis of case bridge are evaluated with considering chloride ion erosion and concrete carbonization, firstly. Then, combining fuzzy theory and fragility analysis, the triangular fuzzy values of resilience parameters under different service period are obtained. Finally, the life-cycle resilience of bridge in different disaster prevention capability is analyzed.","PeriodicalId":45359,"journal":{"name":"International Journal of Structural Integrity","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2023-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46761527","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A comparative study for adaptive surrogate-model-based reliability evaluation method of automobile components","authors":"S. Yang, Debiao Meng, Hongtao Wang, Zhipeng Chen, Bing Xu","doi":"10.1108/ijsi-03-2023-0020","DOIUrl":"https://doi.org/10.1108/ijsi-03-2023-0020","url":null,"abstract":"PurposeThis study conducts a comparative study on the performance of reliability assessment methods based on adaptive surrogate models to accurately assess the reliability of automobile components, which is critical to the safe operation of vehicles.Design/methodology/approachIn this study, different adaptive learning strategies and surrogate models are combined to study their performance in reliability assessment of automobile components.FindingsBy comparing the reliability evaluation problems of four automobile components, the Kriging model and Polynomial Chaos-Kriging (PCK) have better robustness. Considering the trade-off between accuracy and efficiency, PCK is optimal. The Constrained Min-Max (CMM) learning function only depends on sample information, so it is suitable for most surrogate models. In the four calculation examples, the performance of the combination of CMM and PCK is relatively good. Thus, it is recommended for reliability evaluation problems of automobile components.Originality/valueAlthough a lot of research has been conducted on adaptive surrogate-model-based reliability evaluation method, there are still relatively few studies on the comprehensive application of this method to the reliability evaluation of automobile component. In this study, different adaptive learning strategies and surrogate models are combined to study their performance in reliability assessment of automobile components. Specially, a superior surrogate-model-based reliability evaluation method combination is illustrated in this study, which is instructive for adaptive surrogate-model-based reliability analysis in the reliability evaluation problem of automobile components.","PeriodicalId":45359,"journal":{"name":"International Journal of Structural Integrity","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2023-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41777895","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Service life prediction of reinforced concrete structures subjected to corrosion: a comparative study","authors":"Kuleni Fekadu Yadeta, S. Siriwardane, T. A. Mohammed","doi":"10.1108/ijsi-12-2022-0149","DOIUrl":"https://doi.org/10.1108/ijsi-12-2022-0149","url":null,"abstract":"PurposeReliable estimations of the extent of corrosion and time required to reach specific safety limits are crucial for assessing the reliability of aging reinforced concrete (RC) bridges. Engineers and decision-makers can use these figures to plan suitable inspection and maintenance operations.Design/methodology/approachAnalytical, empirical and numerical approaches for estimating the service life of corroded RC structures were presented and compared. The concrete cover cracking times, which were predicted by the previously proposed analytical models, were compared with the experimentally obtained cracking times to identify the model/s for RC bridges. The shortcomings and limitations of the existing models are discussed.FindingsThe empirical models typically depend on the rate of corrosion, diameter of steel reinforcement and concrete cover depth and based on basic mathematical formula. In contrast, the analytical and numerical models contain the strength and stiffness properties of concrete as well as type of corrosion products and incorporate more complex mechanical factors. Four existing analytical models were analyzed and their performance was evaluated against existing experimental data in literature. All the considered analytical models were assumed thick-walled cylinder models. The maximum difference between observed cracking time from different test data and calculated cracking time using the developed models is 36.5%. The cracking times extend with increase in concrete cover and decrease with corrosion current density. The development of service life prediction models that considers factors such as heterogeneity of concrete, non-uniform corrosion along rebar, rust production rate and a more accurate representation of the corrosion accommodating region are some of the areas for further research.Research limitations/implicationsOutcome of this paper partially bridge the gap between theory and practice, as it is the basis to estimate the serviceability of corrosion-affected RC structures and to propose maintenance and repair strategies for the structures. For structural design and evaluation, the crack-width criterion is the greatest practical importance, and structural engineers, operators and asset managers should pay close attention to it. Additionally, repair costs for corrosion-induced serviceability failures, particularly concrete cracking and spalling, are significantly higher than those for strength failures. Therefore, to optimize the maintenance cost of RC structures, it is essential to precisely forecast the serviceability of corrosion-affected concrete structures. The lifespan of RC structures may be extended by timely repairs. This helps stake holders to manage the resources.Practical implicationsIn order to improve modeling of corrosion-induced cracking, important areas for future research were identified. Heterogeneity properties of concrete, concept of porous zone (accommodation effect of pores should be quantified), actua","PeriodicalId":45359,"journal":{"name":"International Journal of Structural Integrity","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2023-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48525272","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental study on shear performance of CFRP-strengthened RC beams with geopolymer adhesive","authors":"Jinliang Liu, Xincheng Su","doi":"10.1108/ijsi-11-2022-0142","DOIUrl":"https://doi.org/10.1108/ijsi-11-2022-0142","url":null,"abstract":"PurposeThe effects of carbon fiber reinforced polymer (CFRP) reinforcement form, adhesive type and pre-crack width on failure mode, shear capacity, deflection response, CFRP strain response and crack patterns of strengthened specimens were investigated.Design/methodology/approachThis paper presents a geopolymer adhesive that matches the performance requirements of CFRP adhesive, which is applied to pre-cracked beams reinforced with CFRP strips. FindingsFor specimens with varying structural properties, two failure modes, the CFRP-concrete interface substrate failure and the fracture failure of CFRP, are observed. Moreover, the shear capacity, ultimate deflection and bending stiffness of the U-shaped CFRP-strengthened beams are enhanced in comparison to the complete-wrapping CFRP-strengthened beams. With an increase in pre-crack width, the increase in shear capacity of RC beams shear-strengthened with CFRP strips is less than that of non-cracked beams, resulting in a limited influence on the stiffness of CFRP-strengthened beams. The comparison of experimental results showed that the proposed finite element model (FEM) effectively evaluated the mechanical characteristics of CFRP-strengthened RC beams.Originality/valueTaking into consideration the reinforcement effect and the concept of environmental protection, the geopolymer adhesive reinforcement scheme is preferable to applying epoxy resin to the CFRP-strengthened RC beams.","PeriodicalId":45359,"journal":{"name":"International Journal of Structural Integrity","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2023-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45295532","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analysis of cracking evolution mode of the monobloc sleeper","authors":"Mohammed Tahi, M. Chikhaoui, M. Chabaat","doi":"10.1108/ijsi-01-2023-0010","DOIUrl":"https://doi.org/10.1108/ijsi-01-2023-0010","url":null,"abstract":"PurposeMonobloc sleepers have several problems related to bending cracking, especially longitudinal cracking and cracking at rail seat under preload release. Therefore, the purpose of this study is to describe the behavior and cracking mode of prestressed concrete railroad sleepers under static loads using the positive test. Experimental tests followed by 3-D numerical models were performed of the same test.Design/methodology/approachTwo steel supports were placed on the rail seat. During a progressive loading, the initiated cracks had approximately the same amplitude as those obtained from the numerical model. The type of cracking depends on the intensity of the applied static load and the loading rate. A validated three-dimensional digital model was established. The obtained results showed a perfect resemblance to the experimental tests. The final design was optimized and verified using a validated numerical simulation.FindingsAt low static loading levels, the first flexural shear cracks appeared at a vertical position located between the two steel supports. At higher static loading levels, bending shear cracks have occurred. The latter are inclined at the steel supports. It was proven that for higher loading levels, shear cracks were the primary mode of failure.Research limitations/implicationsOwing to the sensitivity of monobloc sleepers to technology production, the results are limited by the maximal loading and press used.Practical implicationsNumerical modeling greatly reduces uncertainties in laboratory testing and is an important tool for visualizing and quantifying rail seat cracks to understand behavior and predict collapse.Social implicationsEnsuring human life during rail operations is one of our the long-term priorities. This cannot be done unless the authors manage to master the manufacturing tool for sleepers while controlling the limitation of crack propagation.Originality/valueThe three-dimensional numerical established model has been checked and validated against the experimental results using the positive test to understand the behavior and the cracking mode of prestressed concrete railroad sleepers under static loads. The proposed numerical model has been more refined for a later more complex application by reducing the computation time.","PeriodicalId":45359,"journal":{"name":"International Journal of Structural Integrity","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2023-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45655305","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Gearbox fault diagnosis method based on deep learning multi-task framework","authors":"Yao Chen, Ruijun Liang, Wenfeng Ran, Weifang Chen","doi":"10.1108/ijsi-11-2022-0134","DOIUrl":"https://doi.org/10.1108/ijsi-11-2022-0134","url":null,"abstract":"PurposeIn gearbox fault diagnosis, identifying the fault type and severity simultaneously, as well as the compound fault containing multiple faults, is necessary.Design/methodology/approachTo diagnose multiple faults simultaneously, this paper proposes a multichannel and multi-task convolutional neural network (MCMT-CNN) model.FindingsExperiments were conducted on a bearing dataset containing different fault types and severities and a gearbox compound fault dataset. The experimental results show that MCMT-CNN can effectively extract features of different tasks from vibration signals, with a diagnosis accuracy of more than 97%.Originality/valueVibration signals at different positions and in different directions are taken as the MC inputs to ensure the integrity of the fault features. Fault labels are established to retain and distinguish the unique features of different tasks. In MCMT-CNN, multiple task branches can connect and share all neurons in the hidden layer, thus enabling multiple tasks to share information.","PeriodicalId":45359,"journal":{"name":"International Journal of Structural Integrity","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2023-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47459685","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Temperature patterns obtained in thermoelastic stress test at different frequencies, a FEM approach","authors":"G. Duarte, A. Neves, António Ramos Silva","doi":"10.1108/ijsi-10-2022-0126","DOIUrl":"https://doi.org/10.1108/ijsi-10-2022-0126","url":null,"abstract":"PurposeThe goal of this work is to create a computational finite element model to perform thermoelastic stress analysis (TSA) with the usage of a non-ideal load frequency, containing the effects of the material thermal properties.Design/methodology/approachThroughout this document, the methodology of the model is presented first, followed by the procedure and results. The last part is reserved to results, discussion and conclusions.FindingsThis work had the main goal to create a model to perform TSA with the usage of non-ideal loading frequencies, considering the materials’ thermal properties. Loading frequencies out of the ideal range were applied and the model showed capable of good results. The created model reproduced acceptably the TSA, with the desired conditions.Originality/valueThis work creates a model to perform TSA with the usage of non-ideal loading frequencies, considering the materials’ thermal properties.","PeriodicalId":45359,"journal":{"name":"International Journal of Structural Integrity","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2023-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44747167","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}